Sequential Circuits vs Combinational Circuits

Sequential Circuits:

A sequential circuit is an interconnection of flip-flops and gates. The gates by themselves constitute a combinational circuit, but when included with the flip-flops, the overall circuit is classified as a sequential circuit. It consists of a combinational circuit and several clocked flip-flops. Thus a sequential circuit is specified by a time sequence of external inputs, external outputs, and internal flip-flop binary states.

Combinational Circuits:

A combinational circuit is a connected arrangement of logic gates with a set of inputs and outputs. At any given time, the binary values of the outputs are a function of the binary combination of the inputs. These circuits are employed in digital computers for generating binary control decisions and for providing digital components required for data processing.

Block Diagram of a Combinational Circuit

Difference Between Sequential and Combinational Circuits:

Sequential Circuits
Combinational Circuits
1. It is a logic circuit which generates output based on present input as well as past output.1. It is a logic circuit which generates output based upon present inputs.
2. Memory element is present in sequential logic circuit.2. Memory element is not present in combinational logic circuit.
3. Feedback loop is present.3. Feedback loop is not present.
4. It can store a small amount of data.4. It can't store data.
5. The Clock is utilized for performing triggering functions.5. This Circuits do not rely on the clock.
6. It is used in Flip-flop and latches.6. It is used in adders, encoders, multiplexer, etc.